Surge suppressor device

ABSTRACT

An apparatus and method for protecting hardware devices using a spiral inductor. The surge suppressor protects hardware devices from electric surges by isolating the radio frequency from an inner conductor. The surge suppressor includes a housing, an inner conductor, a surge blocking device, and a spiral inductor. The surge blocking device is inserted in series with the hardware devices for blocking the flow of electrical energy therethrough. The spiral inductor is coupled to the surge blocking device and is shunted to ground for discharging the electrical surge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of application Ser. No. 09/309,397, filed on May7, 1999, now U.S. Pat. No. 6,115,227, issued Sep. 5, 2000 which, inturn, is a continuation of application Ser. No. 09/044,216, filed Mar.18, 1998, now U.S. Pat. No. 6,061,223, which claims priority from U.S.provisional patent application Ser. No. 60/062,097, filed Oct. 14, 1997,the disclosure of which is incorporated by reference herein in itsentirety for all purposes.

BACKGROUND OF THE INVENTION

The present invention generally relates to a surge suppressor and moreparticularly to a surge suppressor having a spiral inductor and a surgeblocking device.

Communications equipment, computers, home stereo amplifiers,televisions, and other electronic devices are increasingly manufacturedusing small electronic components which are very vulnerable to damagefrom electrical energy surges. Surge variations in power andtransmission line voltages, as well as noise, can change the operatingrange of the equipment and can severely damage and/or destroy electronicdevices. Moreover, these electronic devices can be very expensive torepair and replace. Therefore, a cost effective way to protect thesecomponents from power surges is needed.

There are many sources which can cause harmful electrical energy surges.One source is radio frequency (RF) interference that can be coupled topower and transmission lines from a multitude of sources. The power andtransmission lines act as large antennas that may extend over severalmiles, thereby collecting a significant amount of RF noise power fromsuch sources as radio broadcast antennas. Another source of the harmfulRF energy is from the equipment to be protected itself, such ascomputers. Older computers may emit significant amounts of RFinterference. Another harmful source is conductive noise, which isgenerated by equipment connected to the power and transmission lines andwhich is conducted along the power lines to the equipment to beprotected. Still another source of harmful electrical energy islightning. Lightning is a complex electromagnetic energy source havingpotentials estimated at from 5 million to 20 million volts and currentsreaching thousands of amperes.

Ideally, what is needed is a surge suppression device having a compactsize, a low insertion loss, and a low voltage standing wave ratio (VSWR)that can protect hardware equipment from harmful electrical energyemitted from the above described sources.

SUMMARY OF THE INVENTION

The present invention relates to a surge suppressor for dissipatingpower surges. The surge suppressor protects hardware equipment fromelectrical energy surges such as lightning. The surge suppressorincludes an inner conductor and a spiral inductor. The inner conductorpropagates signals therethrough during normal operation and the spiralinductor dissipates electrical energy during a surge condition to aground connection. The spiral inductor is coupled between the innerconductor and the ground connection. The spiral inductor operates at apredefined RF impedance to ground to conduct the signals along the innerconductor during normal operation to allow the RF signal to pass throughthe surge suppressor with minimal or no RF signal loss. The predefinedRF impedance of the inductor is at least 10 times the operatingimpedance, i.e., 500 ohms for a 50 ohms system.

The surge suppressor may also include a surge blocking device. The surgeblocking device is inserted in series with the protected hardware forblocking the flow of electrical energy therethrough. The surge blockingdevice will be transparent to the transmitted RF signal, but will beeffective in blocking the electrical energy surge from traveling throughthe inner conductor to the protected hardware. The spiral inductor iscoupled to the surge blocking device and is shunted to ground fordischarging the electrical energy created by the surge.

When a surge event, such as lightning, occurs, the electrical energy isshunted to ground via the spiral inductor while the surge blockingdevice blocks the destructive lightning and EMP frequencies and theenergy from passing through to the protected hardware.

Advantages of the invention include providing a surge suppressor that ismatched to the system impedance to ensure low voltage standing waveratio (VSWR) which is below 1.1:1 and a low insertion loss which isbelow 0.1 dB. Furthermore, the surge suppressor provides a largefrequency band of operation, a low manufacturing cost, a stackedmechanical assembly for compact size, and low energy and voltagethroughput.

A further understanding of the nature and advantages of the inventionsherein may be realized by reference to the remaining portions of thespecification and the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a circuit diagram of one embodiment of the surgesuppressor in accordance with the present invention;

FIG. 2 illustrates a schematic circuit diagram of another embodiment ofthe surge suppressor in accordance with the present invention;

FIG. 3 illustrates a perspective view of the surge suppressor shown inFIG. 2;

FIG. 4 illustrates a side view of the spiral inductor in accordance withthe present invention;

FIG. 5 illustrates a front view of the surge blocking device inaccordance with the present invention; and

FIG. 6 illustrates an iterative process to determine the inductance ofthe spiral inductor and the capacitance of the surge blocking device.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

In the description that follows, the present invention will be describedin reference to a preferred embodiment that operates as a surgesuppressor. In particular, examples will be described which illustrateparticular features of the invention. The present invention, however, isnot limited to any particular features nor limited by the examplesdescribed herein. Therefore, the description of the embodiments thatfollow are for purposes of illustration and not limitation.

FIG. 1 illustrates a circuit diagram of one embodiment of the surgesuppressor in accordance with the present invention. The surgesuppressor 100 protects hardware and equipment 110 from an electricalsurge that can damage or destroy the hardware and equipment. A surgecondition can arise in many different situations, however, typicallyarises when a lightning bolt 120 strikes a component or transmissionline 105 which is coupled to the protected hardware 110. Lightningsurges consist of D.C. electrical energy and AC electrical energy up toapproximately 1 MHz in frequency.

In this embodiment, the surge suppressor 100 includes a spiral inductor130 having a small foot print design, as shown in FIG. 4. The diameter,surface area, thickness, and shape of the spiral inductor 130 varydepending on the operating frequency and current handling capabilitiesdesired. In the preferred embodiment, an iterative process (describedbelow) is used to determine the diameter, surface area, thickness, andshape of the spiral inductor to meet the user's particular application.The diameter of the spiral inductor 130 of this package size andfrequency range is typically 0.865 inches. The thickness of the spiralinductor 130 of this package size and frequency range is typically 0.062inches. Furthermore, the spiral inductor 130 spirals in an outwarddirection.

The material composition of the spiral inductor 130 is an importantfactor in determines the amount of charge that can be safely dissipatedacross the spiral inductor 130. A high tensile strength material allowsthe spiral inductor 130 to discharge a greater amount of current. In thepreferred embodiment, the spiral inductor 130 is made of a 7075-T6Aluminum material. Alternatively, any material having a good tensilestrength and conductivity can be used to manufacture the spiral inductor130.

The protected hardware 110 can be any communications equipment, PCcomputers, network connectors, or any other type of surge sensitiveelectronic equipment. The protected hardware 110 may also contain asurge blocking device, as shown in FIG. 2, which shields the protectedhardware 110 from an electrical surge.

FIG. 2 illustrates a schematic circuit diagram of another embodiment ofthe surge suppressor in accordance with the present invention. The surgesuppressor 100 is connected to an antenna 170 for receiving a surge.Antenna 170 or any other conducting surface can receive the lightningstrike. Preferably, the surge suppressor 100 is positioned nearest tothe protected hardware 110 to provide maximum protection.

The preferred embodiment includes a spiral inductor 130 for dischargingan electrical surge to ground and a surge blocking device 150 forblocking A.C. and D.C. electrical energy. The spiral inductor 130 of thepreferred embodiment has been described above. Typically, the surgeblocking device 150 is a capacitive device realized in either lumped ordistributed form. Alternatively, the surge blocking device 150 can beparallel rods, coupling devices, conductive plates, or any other deviceor combination of elements which produce a capacitive effect. Thecapacitance of the surge blocking device 150 can vary depending on thefrequency of operation desired by the user. An iterative process(described below) is preferably utilized to determine the capacitance ofthe surge blocking device 150.

During normal operation, protected hardware 110 receives and/ortransmits RF signals through transmission line 105. Hence, the surgesuppressor 100 operates in a bidirectional manner.

During a surge condition, a large amount of electrical energy travelstoward the surge blocking device 150. Hence, in this mode of operationthe surge suppressor 100 operates in a unidirectional manner. The surgeblocking device 150 blocks the electrical energy created by thelightning strike and diverts the electrical energy through the spiralinductor 130 to ground 140. The surge blocking device 150 is designed topass less than ±3 volts D.C., as per IEC 1000-4-5 8/20 usec 20 kAspecification. Spiral inductor 130 should be of sufficient conductivityand cross sectional area to dissipate electrical energy corresponding tothe aforementioned signal specification.

In one embodiment, the minimum frequency range of operation is 1.7 GHzto 2.3 GHz; within which the insertion loss is specified less than 0.1dB and the VSWR is specified less than 1.1:1. The values produced abovecan vary depending on the frequency range, degree of surge protection,and RF performance desired.

FIG. 3 illustrates a perspective view of the surge suppressor shown inFIG. 2. The surge suppressor 100 includes a surge blocking device 250, aspiral inductor 230, an inner conductor 215, and a housing 220 having acavity 222, a surge port 255, and a protected port 260. The innerconductor 215 is positioned concentric with and located in the cavity222 of housing 220. The surge port 255 is coupled to transmission line105 or antenna 170 and the protected port 260 is coupled to theprotected hardware 110, as shown in FIGS. 2 and 3.

During a surge condition, the surge propagates into the surge port 255via the inner conductor 215. Thereafter, the surge is dissipated to aground connection via the spiral inductor 230. Hence, the surge isprohibited from reaching the protected port 260 and the protectedhardware 110.

During normal operating conditions, the inner conductor 215 transmitsand receives RF signals. The inner conductor 215 can be made of anyconductive material. Typically, the inner conductor 215 is a coaxialcable and is made of a beryllium copper material.

Disposed at various locations throughout the housing 220 are insulatingmembers. Preferably, there is a first and a second 226, 228 insulatingmember. The insulating members 226, 228 electrically isolates the innerconductor 215 from the housing 220. The insulating members 226, 228 maybe made of a dielectric material such Teflon which has a dielectricconstant of approximately 2.3. The insulating members 226, 228 aretypically cylindrically shaped with a center hole.

The surge suppressor components located inside the cavity 222 of thehousing 220 will now be described in detail. The surge suppressor 100has various segments each of which are structured to form a desiredimpedance, i.e., 50 ohms. Each adjacent segment is coupled to oneanother. The various segments will be described starting at surge port255 and ending at protected port 260. Each segment will be labeled Athrough H. The inner conductor 215 is located at segments A, B, C, G,and H and has an outer radius of approximately 60 mils.

Segments 215A and 215B include an inner conductor 215 surrounded by anair dielectric. The inner radius of the cavity 222 of segment 215B isapproximately 137.8 mils.

Segment 215C includes an inner conductor 215 supported and surrounded bythe first insulating member 226. The first insulating member 226 has aninner radius of approximately 57.5 mils, an outer radius ofapproximately 200 mils, and a length of approximately 325 mils. Theinner radius of the cavity 222 is approximately 200 mils.

Segment 215D includes an extender 240 that couples the inner conductor215 to the spiral inductor 230. Extender 240 is disposed in the cavity222. At segment 215D, the cavity 222 forms a 45 degree angle. The 45degree angle allows a low discontinuity match between the 50 ohm lineand the spiral inductor 230. The extender 240 has an outer radius ofapproximately 140 mils and is made of a silver plated brass material.

Segment 215E includes a spiral inductor 230 disposed within the cavity222. The spiral inductor 230 has an inner radius of approximately 62.5mils and an outer radius of approximately 432.5 mils. The inner edge 231of the spiral inductor 230 is coupled to inner conductor 215. The outeredge 232 of the spiral inductor 230 is coupled to housing 220. Thespiral inductor 230 may be of a particular known type such as theArchemedes, Logarithmic, or Hyperbolic spiral, or a combination of thesespirals. The inner radius of the cavity 222 is approximately 432.5 mils.The housing 220 is coupled to a common ground connection to dischargethe electrical energy.

During a surge condition, the electrical energy first reaches the inneredge 231 of the spiral inductor 230. The electrical energy is thendissipated through the spirals of the spiral inductor 230 in an outwarddirection. Once the electrical energy reaches the outer edge 232, theelectrical energy is dissipated to ground through housing 220.

Segment 215F includes a surge blocking device 250 disposed within thecavity 222 which has an inner radius of approximately 400 mils. Thesurge blocking device 250 is typically a capacitive device realized ineither lumped or distributed form. The capacitive device includes twoelectrodes. The first electrode includes a first plate 251A and a firsttransition 252A. Likewise, the second electrode includes a second plate251B and a second transition 252B. The radius of each plate 251A, 251Bis approximately 243 mils and the thickness is approximately 50 mils.The radius of each transition 252A, 252B is approximately 92.5 mils andthe thickness is approximately 186 mils. Each plate 251A, 251B is morecapacitive than each transition 252A, 252B. As a result, the surgeblocking device 250 is designed such that the two plates 251A, 251B andtwo transitions 252A, 252B collectively form approximately a 50 ohmimpedance path. Typically, a dielectric material 253 such as Teflon isdisposed between the two plates. The thickness of the dielectricmaterial 253 is approximately 20 mils. The distance between the platescan be varied as well as the dielectric material used. The dimensions,shape, size, and distance between the plates are chosen to achieve adesired impedance for the selected frequency range of operation.Alternatively, the surge blocking device 250 may be located outside thehousing 220.

Segment 215G includes an inner conductor 215 supported and surrounded bythe second insulating member 228. The second insulating member 228 hasan inner radius of approximately 57.5 mils, an outer radius ofapproximately 200 mils, and a length of approximately 150 mils. The sizeand shape of the insulating members 226, 228 are designed such that theyform a structure having a desired impedance, i.e., 50 ohms. The innerradius of cavity 222 is approximately 200 mils.

The housing 220 can be made up of one or more structures for easydisassembly and part replacement. O-rings 245 are used to weather proofthe surge suppressor 100 such that no moisture or water can enter thehousing 220. As shown in FIGS. 3 and 4, the spiral inductor 230 and thesurge blocking device 250 are disposed inside the cavity 222 to achievea compact size. In one embodiment, the spiral inductor 235 and the surgeblocking device 230 are self-aligned within cavity 222.

The surge suppressor 100 is preferably impedance matched to the systemto ensure a low VSWR. Typically, the impedance of the surge suppressor100 is 50 ohms at both the surge port 255 and the protected port 260.

FIG. 4 illustrates a side view of the spiral inductor as shown inaccordance with the present invention. The inner edge 231 forms a radiusof approximately 62.5 mils. The outer edge 232 forms a radius ofapproximately 432.5 mils. The spiral inductor 230 spirals in an outwarddirection. The spiral inductor 230 of a preferred embodiment has threespirals. The number of spirals and thickness of each spiral can bevaried depending on the user's particular application.

FIG. 5 illustrates a front view of the surge blocking device 250 inaccordance with the present invention. The surge blocking device 250 isdescribed throughout the specification, for example, as segment 215F.

FIG. 6 illustrates an iterative process to determine the inductance ofthe spiral inductor. The iterative process can also be used to calculatethe capacitance of the surge blocking device for the user's particularapplication. Initially at step 602, a cutoff frequency is determined bychoosing a lower bandwidth limit and dividing by 8. In addition, adesired impedance is chosen. The cut-off frequency defines the lower endof user bandwidth. The desired impedance is typically 50 ohms, but maybe selected to be another value as needed.

Next at step 604, initial values for L and C are calculated using theequations:

L=Z₀/(12.6*f_(c))  (1)

C=1/(12.6*f_(c)*Z₀)  (2)

where:

Z₀=Desired impedance

f_(c)=Cut-off frequency=low operating limit/8

In the preferred embodiment where the −3 dB cut-off frequency isapproximately 212 MHz and the desired impedance is 50 ohms, the inductorhas a value of 18.7 nH and the capacitive device has a value of 7.5 pF.

Next at step 606, the cavity dimensions of the surge suppressor andinductor constraints are defined. The minimum dimensions of the surgesuppressor's cavity are determined largely by the diameter of theconnector used, i.e, N-type, BNC, etc. The inductor constraints willinclude sizing constraints, such as the inner diameter of the cavity,and operating constraints such as the required conductivity, currenthandling, rigidity, type and thickness of the inductor material used.

Once the inductor's RF value, cavity dimensions and physical constraintsare defined, a spiral inductor is designed to meet all of theserequirements, as shown in step 608. The designed spiral inductor willpossess the calculated inductance to provide the necessary cut-offfrequency, and the physical size and shape to fit into the requiredhousing and conduct the necessary current during a surge withoutfailing. The spiral inductor may be of a particular known type such asthe Archemedes, Logarithmic or Hyperbolic spiral, or a combination ofthese spirals. Further, the spiral inductor may be of a shape resultingfrom two or more overlapped spirals. The spiral inductor is preferablydesigned using a RF modeling system, such as the HP 85123A, so that amore accurate simulation of the inductor can be performed.

Once the spiral has been designed, it is fabricated, placed in a housingidentical to its eventual operating environment, and tested to determineif the measured inductance is approximately equivalent to the desiredinductance, as shown in step 610. As is well known in the art, placing acircuit element within a grounded enclosure introduces parasitic effectswhich must be accounted for if proper operation is to be achieved.

The spiral is tested using conventionally-known RF test equipment suchas a HP 8753 automatic network analyzer. If the test results indicate anunacceptable deviation between measured and desired inductance, thespiral inductor design process is repeated as shown in step 610.

If the measured versus desired inductance is within an acceptable range,a surge suppressor having a thru line is measured, as shown in step 612.The thru measurement is made to provide a baseline insertion lossmeasurement over the RF frequency of interest. In the preferredembodiment, the frequency range of interest is 1.7 GHz to 2.3 GHz.

Next at step 614, a surge suppressor having a thru line of the samedimensions measured in step 612 and the spiral inductor coupled from thethru line to ground (in shunt) is measured for insertion loss over theRF frequency range of interest. This measurement can then be compared tothe previous thru measurement to indicate how much insertion lossdegradation occurs with the addition of the shunt spiral inductor. Ifthe insertion loss of the thru line plus shunt inductor is not within anacceptable range, steps 608, 610, and 612 are repeated. Othermeasurements, for instance, single port measurements may be used insteadof, or in addition to the insertion loss measurement for qualifying thesurge suppressor.

If the insertion loss of the thru line plus shunt spiral inductor iswithin an acceptable range, a surge blocking series capacitive device isdesigned for inclusion within the surge suppressor, as shown in step616. The capacitive device is designed to possess the calculatedcapacitance, fit within the specified inner diameter of the cavity, andpossess the physical properties to withstand a surge condition. Thecombination of the thru line, shunt spiral inductor, and seriescapacitive device may be simulated using a two or three dimensional CADsystem. If used, modifications may be made to the design of the shuntspiral inductor, series surge blocking capacitive device and/or theirseparation to further optimize the surge suppressor's performance. Inparticular, it has been found that varying the shape and size of thecapacitive device's electrodes results in changing the effectiveinductance of the shunt spiral inductor to further optimize circuitperformance.

At step 618, a new surge suppressor incorporating the thru line, theshunt spiral inductor, and the series surge blocking capacitive deviceis fabricated and tested using the aforementioned or similar testingequipment. If the surge suppressor exhibits unacceptable insertion lossover the desired frequency range, the capacitive device design and/orits location along the thru line may be modified to tune the response tothe desired level. Specifically, the capacitive device's gapping,diameter, and dielectric material may be altered to tune the insertionloss response within acceptable limits. If capacitive devicemodification is unsuccessful in tuning the desired parameter(s) towithin acceptable limits, steps 608, 610, 612, 614, and 616 arerepeated.

If the surge suppressor exhibits an acceptable insertion loss and/orother qualifying parameters, it is submitted for RF power handling andenvironmental testing, as shown in step 620. Specifically, the surgesuppressor is exposed to high levels of RF energy and environmental,temperature and vibrational conditions likely to be experienced duringoperation. If the surge suppressor fails to operate over a predeterminedrange, steps 608, 610, 612, 614, 616, and 618 are repeated.

If the surge suppressor has sufficient RF power handling capability andis able to withstand an acceptable range of environmental stress, it issubjected to surge qualification, as shown in step 622. Surgequalification may entail exposing the surge suppressor to high currentpulses under various environmental conditions to simulate a lightningstrike.

Other embodiments of the design process are of course possible. Forinstance, in the embodiment of the surge suppressor having only a shuntspiral inductor, only steps 606, 608, 612, 614, 620 and 622 need beperformed. Specifically, only the inductance value of the spiral shuntinductor need be determined and tested. Subsequently, the insertion lossand/or other parameter(s) of a thru line is used as the qualifyingparameter to determine if the thru line plus the shunt spiral inductoroperates within an acceptable window within the desired frequency range.Finally, RF power handling, environmental, and surge qualificationoccurs as described above.

Although the preferred embodiment is shown with a particular capacitivedevice and a spiral inductor, it is not required that the exact elementsdescribed above be used in the present invention. Thus, the values ofthe capacitive device and the spiral inductor are to illustrate oneembodiment and not to limit the invention.

The invention has now been explained with reference to specificembodiments. Other embodiments will be apparent to one of ordinary skillin the art. It is therefore not intended that this invention be limited,except as indicated by the appended claims.

What is claimed is:
 1. A surge suppressor comprising: a conductorconfigured to receive an electrical surge; and an inductor having aninner arc and an outer arc, the inner arc having a smaller radius thanthe outer arc, the inductor being positioned proximate to the conductorso that the electrical surge can propagate from the conductor to theinductor.
 2. A surge suppressor as defined in claim 1, wherein theconductor defines an axis and the inductor defines a first plane that issubstantially perpendicular to the axis.
 3. A surge suppressor asdefined in claim 2, further comprising a capacitive device positionedalong a second plane that is substantially parallel to the first plane.4. A surge suppressor as defined in claim 3, wherein the capacitivedevice is selected from a group consisting of a capacitor, parallelrods, coupling devices, and conductive plates.
 5. A surge suppressor asdefined in claim 1, wherein the conductor is a coaxial line.
 6. A surgesuppressor as defined in claim 1, further comprising a capacitor thatblocks the electrical surge so that the electrical surge travels fromthe inner arc to the outer arc.
 7. A surge suppressor as defined inclaim 6, wherein the outer arc is connected to a ground that dischargesthe electrical surge.
 8. A surge suppressor as defined in claim 1,farther comprising a housing having a cavity configured to hold theconductor and the inductor therein.
 9. A surge suppressor as defined inclaim 8, further comprising a capacitor positioned proximate to theinductor and disposed within the cavity.
 10. A surge suppressor asdefined in claim 1, wherein the inductor has an impedance of at least500 ohms at a frequency of between 1.7 GHz and 2.3 GHz.
 11. A surgesuppressor comprising: a housing defining a chamber having a centralaxis; a conductor disposed in the chamber of the housing and extendingsubstantially along the central axis of the chamber, the conductorconfigured to carry an A.C. signal and a D.C. surge; an inductor havingan inner arc connected to the conductor and an outer arc connected tothe housing, the inner arc having a smaller radius than the outer arc,the inductor having a curved shape between the inner arc and the outerarc; and a capacitive device connected to the conductor and configuredto block the D.C. surge so that the D.C. surge is directed along theinductor, from the inner arc to the outer arc, to the housing.
 12. Asurge suppressor as defined in claim 11, wherein the housing dischargesthe D.C. surge.
 13. A surge suppressor as defined in claim 11, furthercomprising a ground connected to the housing, to discharge the D.C.surge.
 14. A surge suppressor as defined in claim 11, wherein thecapacitive device is positioned in the chamber of the housing.
 15. Asurge suppressor as defined in claim 11, wherein the capacitive devicehas a first capacitive plate and a second capacitive plate coupled withthe inductor, the first capacitive plate substantially parallel to thesecond capacitive plate.
 16. A surge suppressor as defined in claim 11,wherein the conductor has a central axis that is positioned insubstantially alignment with the central axis of the chamber of thehousing.
 17. A surge suppressor as defined in claim 11, wherein theinductor has a central axis that is positioned in substantiallyalignment with the central axis of the chamber of the housing.
 18. Asurge suppressor comprising: means for propagating a signal and a surge;means for blocking the surge coupled to the means for propagating; andmeans for shunting the surge to a ground coupled to the means forpropagating wherein the means for shunting provides a planar curvedpath.
 19. A surge suppressor as defined in claim 18, wherein the meansfor propagating is an inductor having an inner arc and an outer arc, theinner arc having a smaller radius than the outer arc, the inductorhaving a curved shape between the inner arc and the outer arc.
 20. Asurge suppressor as defined in claim 18, wherein the means for blockingthe surge passes less than ±3 volts D.C.
 21. A surge suppressor asdefined in claim 20, wherein the means for blocking the surge isselected from a group consisting of a capacitor, parallel rods, couplingdevices, and conductive plates.
 22. A surge suppressor as defined inclaim 1, further comprising two conductive plates positionedsubstantially parallel to one another, positioned proximate to theinductor, and configured to block the electrical surge.
 23. A surgesuppressor as defined in claim 8, wherein the housing comprises twostructures detachable from one another.
 24. A surge suppressor asdefined in claim 11, wherein the housing comprises two structuresdetachable from one another.
 25. A surge suppressor as defined in claim15, further comprising a dielectric material sandwiched between thefirst capacitive plate and the second capacitive plate.
 26. A surgesuppressor as defined in claim 20, wherein the means for shunting thesurge is an inductor having a planar configuration.
 27. A surgesuppressor comprising: a housing defining a chamber having a centralaxis, the housing being connectable to a ground; a conductor disposed inthe chamber of the housing and extending substantially along the centralaxis of the chamber; an inductor disposed in the chamber of the housing,the inductor having an inner edge coupled to the conductor, an outeredge coupled to the housing, and curved planar member configured tofacilitate an electrical flow path for a D.C. surge from the conductorto the housing; and a capacitor connected in line to the conductor andconfigured to block the D.C. surge so that the D.C. surge is directedalong the curved planar member of the inductor to the housing.
 28. Asurge suppressor as defined in claim 26, wherein the housing comprisestwo structures detachable from one another.
 29. A surge suppressor asdefined in claim 26, further comprising an insulating member toelectrically isolate the conductor from the housing.
 30. A surgesuppressor as defined in claim 26, wherein the curved planar member hasa shape selected from a group consisting of an archemedes spiral,logarithmic spiral, and hyperbolic spiral.
 31. A surge suppressor asdefined in claim 26, wherein the inductor further comprises a secondcurved planar member configured to facilitate another electrical flowpath for the D.C. surge from the conductor to the housing.
 32. A surgesuppressor as defined in claim 31, wherein the second curved planarmember has a shape selected from a group consisting of archemedesspiral, logarithnic spiral, and hyperbolic spiral.
 33. A surgesuppressor as defined in claim 27, wherein the inductor furthercomprises an inner ring forming the inner edge and connected to thecurved planar member.
 34. A surge suppressor as defined in claim 27,wherein the inductor further comprises an outer ring forming the outeredge and connected to the curved planar member.
 35. A surge suppressoras defined in claim 27, wherein the capacitor has a first capacitiveplate and a second capacitive plate coupled with the inductor, the firstcapacitive plate substantially parallel to the second capacitive plate.36. A surge suppressor as defined in claim 35, wherein the capacitorfurther comprises a dielectric material sandwiched between the firstcapacitive plate and the second capacitive plate.
 37. A surge suppressoras defined in claim 27, wherein the capacitor passes less than ±3 voltsD.C.
 38. A surge suppressor as defined in claim 27, wherein thecapacitor is disposed within the chamber of the housing.
 39. A surgesuppressor as defined in claim 27, wherein the conductor is a coaxialline.